1. Field of the Invention
The invention concerns a device which makes it possible to detect a difference between the speeds of rotation of two revolving shafts so that this difference in speeds may be noted on an appropriate device or so as to control the speed of rotation of one of the shafts as a function of the speed of rotation of the other shaft, or to trigger an automatic reaction when the difference in speeds of rotation of the two shafts reaches a given threshold.
2. Description of the Prior Art
Generally, when the speed of rotation of one shaft must be subject to the speed of rotation of another shaft, each speed of rotation is determined by using an independent rotational speed detector including dead-heads which revolve with the corresponding shaft, acting against a resisting spring to move a movable body, and the movable bodies on the two detectors of rotational speed are generally interconnected by a mechanism which, in the majority of cases, involves a system of levers and at least one cam. A device of this type is described in U.S. Pat. No. 2,861,638 of Sept. 19, 1957 by R. A. Grosselfinger et al.
Such devices have the drawback of being complicated, as they include two independent speed detectors each of which has a movable body and a resisting spring, as well as an intermediary mechanism interconnecting the movable bodies in each of the two detectors.
Another known type of device, for example that in U.S. Pat. No. 1,856,024 of Mar. 10, 1924, involves two independent ball-type regulators which influence one another by means of a coupling spring. However, these devices do not allow for a precise relationship in controlling the speeds of rotation of the two shafts, as the coupling has only a dynamic effect.
Moreover, there is no known mechanism for detecting differences in speeds of rotation which makes it possible to freely trigger an automatic device of any kind such as a micro circuit breaker or valve.